Introduction to Biology

Skills for the Biologist 1. Data table: The data table is used to record numerical data. The information is organized by arranging observations into columns with appropriate headings.

Skills for the Biologist 2. Bar Graph(Histogram): A bar graph allows a scientist to compare data.

Skills for the Biologist 3. Line Graph: A line graph is used to show relationships between two or more variables.

Skills for the Biologist Independent variable: is placed on the horizontal (bottom) or X axis Independent variables are usually the variables that the scientist controls. Ex. Temperature, amount of light, etc. Dependent variable: is placed on the vertical (side) or Y-axis. Dependent variables depend on the changes in the independent variable.

Skills for the Biologist a) Independent variable: is placed on the horizontal (bottom) or X axis Independent variables are usually the variables that the scientist controls. Ex. Temperature, amount of light, etc. b) Dependent variable: is placed on the vertical (side) or Y-axis. Dependent variables depend on the changes in the independent variable.

The Scientific Method The Scientific Method The technique used by scientists to solve problems and gain scientific information. The Scientific Method is a process of logical thinking. Steps of the scientific method: 1. Problem 2. Hypothesis - Claim 3. Experimentation 4. Observations - Evidence 5. Conclusions

The Scientific Method (cont.) Problem: A problem must be stated. It is a question for which a scientist is trying to find an answer. Ex. Will a plant grow in complete darkness? Hypothesis: An educated guess about the answer to the problem. The hypothesis is based on information which has been learned about the problem. It is your CLAIM to a possible answer to the problem Ex. I think that...

The Scientific Method (cont.) Experimentation: set up a controlled experiment that will test the hypothesis. a) Controlled experiment: an experiment which tests only one factor. Ex. 2 of the same species plant, one grown in complete darkness, and the other grown in regular light Variable: Is the factor to be tested Ex. amount of light

Variables Independent Variable – Dependent Variable – something that is changed by the scientist Controlled by the scientist What is tested What is manipulated Dependent Variable – something that might be affected by the change in the independent variable Changes because of the experiment DATA What is observed What is measured The data collected during the investigation

Variables A exact duplicate experiment without the variable. Independent Variable – Dependent Variable – Controlled Variable a variable that is not changed Also called constants Allow for a “fair test” A exact duplicate experiment without the variable.

Identify the variables in this investigation. Students of different ages were given the same jigsaw puzzle to put together. They were timed to see how long it took to finish the puzzle

What was the independent variable? Ages of the students Different ages were tested by the scientist

What was the dependent variable? The time it to put the puzzle together The time was observed and measured by the scientist

What was the control? Same puzzle All of the participants were tested with the same puzzle. It would not have been a fair test if some had an easy 30 piece puzzle and some had a harder 500 piece puzzle.

Draw the Data Table

Identify the variables in this investigation. An investigation was done with an electromagnetic system made from a battery and wire wrapped around a nail. Different sizes of nails were used. The number of paper clips the electromagnet could pick up was measured.

Independent variable: Sizes of nails These were changed by the scientist

Number of paper clips picked up Dependent variable: Number of paper clips picked up The number of paper clips observed and counted (measured)

Controlled variables: Battery, wire, type of nail None of these items were changed

Draw the Data Table

The Scientific Method (cont.) Observations / Claims: Measurements, notes, records of things seen, heard, felt, during the experiment. Usually, observations are made using units of measure. Conclusions: explanations of the problem based on the observations. True conclusions must be backed up by observations and data from the experiments. USE DATA Ex. I conclude that ………….. because …………...

The Life Processes Life Processes Life Functions There is not simple definition for life. However many characteristics of living things have been defined. Life Processes Transport: Absorption and distribution of materials within an organism. (Circulation) 2. Excretion: Removal of waste products that the organism itself has made. 3. Nutrition: All activities that an organism does to get materials from the environment and prepare them for use.

The Life Processes Reasons for Nutrition: Energy: all living things need energy Raw materials: all living things need raw materials for growth and repair Steps in Nutrition: Ingestion: taking material (food) in from the environment Digestion: breakdown of food materials into simpler forms that an organism can use Egestion: getting rid of food wastes (feces) Types of nutrition Autotrophic: (self feeder) an organism that can synthesize its own food (plants) Heterotrophic: (other eater) an organism that cannot synthesize its own food (humans)

The Life Processes 4. Growth: Using the products of synthesis to increase cell size or number 5. Respiration: Chemical process by which an organism obtains ENERGY from food materials in order to maintain life functions. Respiration in this case refers to Cellular Respiration, not breathing 6. Regulation: The coordination and control of the activities of an organism and the response to its environment using nerve impulses or hormones

The Life Processes 7. Reproduction: The production of new individuals. This must occur in order for a species to survive, however, an individual organism does not need to reproduce in order to survive. 8. Synthesis: The process by which an organism builds large molecules from smaller ones Ex: waxes, drugs, poisons, mucus All of the chemical reactions responsible for the life functions, occurring in an organism are known as that organism’s Metabolism…

The Life Processes The goal of these chemical reactions and the life functions is to maintain “Homeostasis” or a “Same State”. Keeping a constant internal environment. Examples: House Thermostat Body temp remains relatively constant (37 degrees C) The amount of glucose (sugar) in the blood needs to be within a certain range.

Key Vocabulary Length: the distance from point to point Mass: describes an amount of matter Volume: describe the space occupied by matter Temperature: measures the average kinetic energy in matter Gram: a small amount of mass used to measure small objects Kilogram: a large amount of mass used to measure large objects Meter: the basic unit of length Centimeter: a small unit of measurement used for small distances Kilometer: a large unit of measurement used for large distances Liter: the basic unit of volume Graduated cylinder: an instrument used to measure volume Celsius: the Metric system for recording temperature Fahrenheit: the English system for recording temperature

Key Vocabulary Assumption: a possibility based on observations 15)  Bias: tendency to favor, prejudice 16)   Conclusion: decision about an experiment based on results and hypothesis 17)   Controlled Experiment: all variables are the same except for the tested one 18)   Data: collected results from tests during experiments 19)  Variable: one factor different from the conditions found in the control  20)  Dependent variable: what is measured because of the independent variable  21)  Independent variable: the factor that influences the dependent variable Evidence: support for something that is true or not true 23)  Experiment: series of tests to support or refute a hypothesis 24)   Hypothesis: an educated guess based on available information 25)   Inference: a conclusion based on observations 26)   Law: a fact based on proven evidence 27)   Model: representation to explain a process or structure  28)   Observation: information collected with the senses  29)   Research Plan: initial stage of an experiment 30)   Testing: to try something based on research 31)   Theory: accepted as true that may or may not be true 32)  Control: standard of comparison